In recent years, the number of the pixels of a solid-state imaging device such as a CCD image sensor is heightened. As a method which readouts signals from such a high-pixel solid-state imaging device at a high speed, a pixel mixture readout method or a down sampling readout method is utilized conventionally.
As one example of the conventional pixel mixture readout method, for example, a pixel mixture readout method that mixes nine pixels and readouts signals is disclosed in a color solid-state imaging device according to Patent Document 1. The conventional pixel mixture readout method as disclosed in Patent Document 1, performs pixel mixture of the equal number of pixels and readouts signals after pixel mixture.
In other words, in all readout signals that are readout by the conventional pixel mixture readout method, pixel mixture of the equal number of pixels is performed.
However, since the signals that are readout by the conventional pixel mixture readout method are the signals obtained by performing pixel mixture of the same number of pixels, the properties and features of these signals are equal. That is to say, there is a problem that the signals readout by the conventional pixel mixture readout method can generate only one kind of image.
Therefore, it is impossible to generate an image having high added value (for example, the image such as a wide dynamic range image or a super-resolution image obtained by a super-resolution processing) based on the signals readout by the conventional pixel mixture readout method.